South Korean conglomerate Doosan Group has become the largest shareholder of a local chip-testing firm, Tesna, in a move to secure a footing in the surging semiconductor market.

According to Doosan Wednesday, the group recently purchased a 38.7 percent stake in Tesna for 460 billion won ($373.1 million).

Founded in 2002, Tesna has specialized in testing various chips, including processors for smartphones, camera image sensors and radio frequency chips for wireless communications.

The firm, in particular, is a market leader in wafer-testing services here. A wafer is a thin plate on which thousands of chips are printed. Tesna offers services to pick out defective chips.

Its key clients are Samsung Electronics and SK hynix. As the two big customers aggressively expand their chip businesses, Tesna has also enjoyed rapid growth in recent years.

Last year alone, sales and operating profit jumped 56.6 percent and 76.8 percent to 207.5 billion won and 54 billion won, respectively, compared to the year before.

Through the latest acquisition, Doosan expects synergies between its core industrial machinery business and Tesna’s chip-testing capabilities.